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An anonymous reader writes "Researchers at Purdue say the merging of plasmonics and nanophotonics is promising the emergence of new 'quantum information systems' far more powerful than today's computers. Plasmons are quasiparticles that combine electrons and photons. And by using them in place of the simple electrons of today's computers, they could overcome limitations in the operational speed of conventional integrated circuits. The technology hinges on using single photons for switching and routing in computers that would harness the exotic principles of quantum mechanics.'"

Optical computer - yes there were articles about these in Scientific American in the early 80s - anyone got the reference? Even older I am sure. And holography was going to replace magnetic memory of all sorts. I think there is an article about flying cars in that issue. Oh and one day we'd all have portable phones as small as Star Trek communicators...

Forget the whole computer, just a nice fat light pipe between the CPU and RAM, maybe a second between the PCIe and CPU but but great, thanks loads. Nowadays it seems like no matter how much RAM you stuff keeping the CPU and GPU fed ends up being the problem. SSDs for the OS can kill a lot of the HDD problem but in the end it all comes down to feeding the chips and a nice light pipe between the chips and RAM would probably make today's PCs feel like a 386 trying to run Win98.

I just read a slashdot summary and it wasn't saturated with acronyms that have several completely different meanings depending on your field of expertise.

Well, I noticed a lot of use of the term "quantum", which has radically different meanings to different people. In this case, I see strong evidence that they were using the Marketing meaning of "quantum", i.e., something vaguely defined but mysterious and powerful that will impress the marks^Wcustomers when you throw it into your ad copy.

They couldn't have been using the physicists' meaning of "quantum"; it's been decades since you could understand how a computer's solid-state components worked without

Well, as always, it's harder than it looks because people are so bad at explaining things well.

Actually, it's all about statistics and likelinesses. And as you might know, those are well-know topics for mathematicians.

I think it's pretty weird that our computers are thinking all black and white, when that is never ever the case, except for the effects of quantization.Say you want to calculate something. In quantum computing, you would get not one result, but all of them in an overlaying state. (Like a distr

"Well, no, since the functions you would want to feed the result to would just as well accept such values, allowing you to continue with them as if they were normal values. (Of course you should still be aware of the differences, as they can be both harmful and useful.)"

Okay, let's try to simplify it even more. Quantum computers have gates just like ordinary computers. There's a difference, though: instead of acting only on a single value, they act on a whole bundle of them at once (that's the probability distribution). You can in effect calculate a function on many inputs at once, but you can't reach behind the curtain and pick all the answers (or any answer you want) from the result. When you do ask the computer to reveal an answer, you get a random answer from the entir

The whole point in quantum computing is that it is not random but completely deterministic through the wavefunction. Only the measurements of quantum states are "random" and this is because you are forcing the system to take one of a few discrete values. Through multiple measurements, we can pin down the expectation (average) value of the observable which should be constant for constant inputs on a certain calculation.

Actually for most algorithms you don't need statistics, because you can easily check if your solution is the correct one (e.g. prime factorization: Just multiply the numbers you got, and see if the original number results). If it is, you're ready, if not, you run the program again. The trick is to get into a state where the correct answer is very likely to occur. Or at least significantly more likely than by pure guessing.

For a given starting state, the ending state is determined by the operations in the quantum computer. It is only in trying to measure the resulting qubits that the probability interpretation comes into it.

The research isn't a scam, just as fusion research isn't a scam. It becomes a scam only when people claim to have working models. Otherwise, it is at worst fraud. And generally, just failure. However, the potential is really there. Any competent scientist will tell you we are quite some ways away from working quantum computers. TV shows and magazines like "Scientific" America like you to think they are close (gets you excited and buying whatever they're selling), but all the real science knows that we have

Or very well may never get there. And even if we get there, it is by far not that much batter to what we have now. Quite a few hard problems stay hard, even with working quantum computers. And yes, I have talked to an expert in the field.

The "almost a scam" is claiming great potential n order to get grant money. This is just dishonest.

That's a cute catchphrase at the end of the summary, but it means even less than usual as quantum buzz words go. Most non-physicists have a little, somewhat fuzzy idea about Heisenberg's uncertainty, and conjure up this idea where everything in QM is spooky weird juju, but what does it mean in a case like this? Photons don't have that sort of situation when it comes to uncertainty. A Photon has a fixed velocity, known to incredible accuracy, and if that part